/*
 * @author : TF-BJ-C064
 * @creation : 2014-7-23 下午3:57:39
 * @description : 
 *
 */

package com.base;

import org.apache.log4j.Logger;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.dao.ParkManagerDao;

public class HibernateUtil {
	
	private static final Logger log = Logger.getLogger(ParkManagerDao.class);
	
	private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";  
	private static final ThreadLocal localSession = new ThreadLocal();  
	private static final ThreadLocal localTransaction = new ThreadLocal();  
	private  static Configuration configuration = new Configuration();  
	private static SessionFactory sessionFactory;  
	private static String configFile = CONFIG_FILE_LOCATION;  

	static {  
		try {  
			//方式一
//			configuration.configure(configFile);
//			sessionFactory = configuration.buildSessionFactory();  

			//方式二
			String[] configLocations = new String[] {"classpath:applicationContext.xml"}; 
			ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext(configLocations); 
			sessionFactory =  ctx.getBean("sessionFactory", SessionFactory.class);

		} catch (Exception e) {  
			System.err.println("%%%% Error Creating SessionFactory %%%%");  
			e.printStackTrace();  
		}  
	}  
	private HibernateUtil() {  
	}  

	/** 
	 * Returns the ThreadLocal Session instance.  Lazy initialize 
	 * the <code>SessionFactory</code> if needed. 
	 * 
	 *  @return Session 
	 *  @throws HibernateException 
	 */  
	public static Session getSession() throws HibernateException {  
		Session session = (Session) localSession.get();  

		if (session == null || !session.isOpen()) {  
			if (sessionFactory == null) {  
				rebuildSessionFactory();  
			}  
			session = (sessionFactory != null) ? sessionFactory.openSession()  : null;
//			log.info(HibernateUtil.class + " session.open()");
			localSession.set(session);  
		}  

		return session;  
	}  

	/** 
	 *  Rebuild hibernate session factory 
	 * 
	 */  
	public static void rebuildSessionFactory() {  
		try {  
			//方式一
//			configuration.configure(configFile);  
//			sessionFactory = configuration.buildSessionFactory();  

			//方式二
			String[] configLocations = new String[] {"classpath:applicationContext.xml"}; 
			ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext(configLocations); 
			sessionFactory =  ctx.getBean("sessionFactory", SessionFactory.class);

		} catch (Exception e) {  
			System.err.println("%%%% Error Creating SessionFactory %%%%");  
			e.printStackTrace();  
		}  
	}  

	/** 
	 *  Close the single hibernate session instance. 
	 * 
	 *  @throws HibernateException 
	 */  
	public static void closeSession() throws HibernateException {  
		Session session = (Session) localSession.get();  
		localSession.set(null);  

		if (session != null && session.isOpen()) {
			session.flush();
			session.close();  
//			log.info(HibernateUtil.class + " session.close()");
		}  
	}  

	/** 
	 *  return session factory 
	 * 
	 */  
	public static SessionFactory getSessionFactory() {  
		return sessionFactory;  
	}  

	/** 
	 *  return session factory 
	 * 
	 *  session factory will be rebuilded in the next call 
	 */  
	public static void setConfigFile(String configFile) {  
		HibernateUtil.configFile = configFile;  
		sessionFactory = null;  
	}  

	/** 
	 *  return hibernate configuration 
	 * 
	 */  
	public static Configuration getConfiguration() {  
		return configuration;  
	}  

	/** 
	 * 开始当前线程中Hibernate Session的事务 
	 * @return Transaction 
	 * @throws HibernateException 
	 */  
	public static Transaction beginTransaction() throws HibernateException {  
		Transaction tx = (Transaction)localTransaction.get();  
		if(tx == null || tx.wasCommitted() || tx.wasRolledBack()){  
			Session session = getSession();   
			tx = (session != null) ? session.beginTransaction() : null;  
			localTransaction.set(tx);  
		}  

		return tx;  
	}  

	/** 
	 * 提交当前线程中Hibernate Session的事务 
	 * @throws HibernateException 
	 */  
	public static void commitTransaction() throws HibernateException {  
		Transaction tx = (Transaction)localTransaction.get();  
		localTransaction.set(null);  
		if(tx != null || (!tx.wasCommitted() && !tx.wasRolledBack())){  
			tx.commit();  
		}  
	}  
	/** 
	 * 回滚当前线程中Hibernate Session的事务 
	 * @throws HibernateException 
	 */  
	public static void rollbackTransaction() throws HibernateException {  
		Transaction tx = (Transaction)localTransaction.get();  
		localTransaction.set(null);  
		if(tx != null || (!tx.wasCommitted() && !tx.wasRolledBack())){  
			tx.rollback();  

		}  
	}  

	/** 
	 * 当前Hibernate Session是否打开 
	 * @return 
	 */  
	public static boolean isOpenSession() {  
		Session session = (Session) localSession.get();  
		if (session != null && session.isOpen()) {  
			return true;  
		}  
		return false;  
	}  
}
